Remote surveillance is common for security, law enforcement, intelligence, and military purposes. For example, shopping centers, police stations, and other facilities catering to the public often have closed-circuit television (CCTV) cameras or other devices monitoring members of the public in the facility. In another example, pole-mounted cameras have been used for traffic enforcement. One type of surveillance that is on the rise is drone surveillance. Unmanned aerial vehicles (UAVs, also known as “drones”) are aircraft that do not carry human pilots or passengers, and are commonly used for surveillance and combat. Drones can be configured as fixed wing aircraft, helicopters, or other aerial vehicles. A human pilot generally controls a drone using a wireless link from one or more ground stations, but drones can include autonomous systems that perform the functions normally executed by a pilot. Drones serve to carry sensors and permit those sensors to interact with their environments in order to collect data. Drones can be used, for example, to carry out surveillance or intelligence-gathering missions using a variety of optical or other sensors, to transport goods or passengers, or to locate and respond to threats.
Various software exists for detecting moving objects or recognizing faces in captured image data, and then displaying an indicator of the detection. Various software also exists for tracking such detected image features as they move. Moreover, various techniques are used to improve the visibility of objects in captured image data. For example, military forces wear IR beacons in combat areas. These IR beacons blink in infrared wavelengths. This renders friendly forces visible in an IR camera view, reducing the probability of casualties due to friendly fire.
Drones can range in size from, e.g., small units weighing grams, to airplanes with wingspans over ten feet, to full-sized airplanes such as bombers. Particularly with smaller units, drones can permit covert surveillance of persons in public. For example, a drone airplane with a wingspan of approximately 10′, painted appropriately, with an electric drive, can be effectively invisible and inaudible to persons on the ground at an altitude of as little as 500′ above ground level (AGL). There is, therefore, a need of implementing the rights of people to be free from surveillance without cause, e.g., privacy and due-process rights, especially when the surveillance is being carried out by a small, unobtrusive drone. This need can also pertain to surveillance carried out by fixed cameras such as security or traffic cameras.